To remove the manifold, first disconnect the cable from the negative terminal of the battery. Raise the front of the vehicle and support it securely on jackstands, disconnecting the wiring from the oxygen sensor only if it interferes with manifold removal. Apply penetrating oil to the nuts and springs retaining the catalytic converter to the manifold, then remove the nuts and separate the converter from the manifold, taking care not to damage the oxygen sensors. For models from 2006.5 and later, remove the complete front muffler assembly. In the engine compartment, remove the upper heat shield from the manifold, ensuring the upper oxygen sensor is removed for those later models, and unbolt the exhaust manifold brace. Disconnect any other interfering brackets, which may vary by vehicle, and then remove the nuts to detach the manifold and gasket. For installation, use a scraper to clean all old gasket material and carbon deposits from the mating surfaces, checking the manifold for warpage if the gasket shows signs of leaking. Position a new gasket over the cylinder head studs, install the manifold, and thread the mounting nuts into place. Tighten the nuts/bolts from the center out to the specified torque, then reinstall the remaining parts in reverse order. Finally, run the engine and check for exhaust leaks.